Planet carrier assemblies that are used in planetary gear transmissions have a carrier or case in which a plurality of pinion gears are rotatably mounted on pinion pins. It is preferable that the pinion pins be secured from movement in the planet carrier both axially and rotatably.
One method of securing the pinion pins in the planet carrier is the process of staking. Staking requires relatively high pressing forces to be used to reshape the outer surface of the pinion pin into an interference with the planet carrier. This high pressing force can result in some distortion to the carrier thereby leading to undesirable noise within the planetary system. Since the pinion gears are normally mounted on needle bearings on the pinion pins, very low friction forces are present to cause rotation of the pinion pins.
Another process for retaining the pinion pins within the carrier is welding, which of course applies some heat to the carrier and pin during the welding process. However, this process is effective in preventing pin movement relative to the carrier housing or case.
A further method is the use of locking rings, which surround each pinion pin and thereby prevents axial movement. However, the locking rings do not necessarily prevent rotational movement relative to the case.